1. Field of the Invention
The present invention relates to a dispersion of a water-immiscible phase in an aqueous external or continuous phase by means of lipid vesicles comprising a silicone surfactant, and to its use for the treatment of the skin, the mucous membranes, the nails, the scalp and/or the hair.
"Lipid vesicles" is understood to mean particles formed of a lamellar phase consisting of one or more concentric sheets, these sheets comprising one or more bimolecular layers of amphiphilic lipids encapsulating an aqueous phase. The encapsulated aqueous phase may contain water-soluble active substances and the bimolecular layers of amphiphilic lipids may contain lipophilic active substances.
2. Description of Background
It is known in the cosmetic and dermatological fields to apply to the skin compositions in the form of aqueous dispersions containing a water-immiscible phase and lipid vesicles which bring about the dispersion of the water-immiscible phase in the aqueous phase.
Thus, documents FR-A-2,490,504 and FR-A-2,485,921 describe the stabilization of a dispersion of droplets of a water-immiscible liquid and especially of oil, by means of lipid vesicles without the need to introduce into the dispersion another stabilizing agent and especially an emulsifier. The vesicles described in these documents are obtained from ionic or nonionic lipids. However, these dispersions have the disadvantage of giving a sticky texture which makes their use unpleasant. This disadvantage is overcome by the choice of the oils.
Moreover, to obtain a sufficiently thick structure, gelling agents are generally added to these oil dispersions. Unfortunately, the nature of these vesicles limits the quantity of gelling agent to be used and therefore limits the consistency of the composition.
In addition, a cosmetic composition most often contains one or more active agents. However, this type of vesicle also limits the concentration of certain active agents. For example, glycerine can only be used in a limited quantity so that the texture is not sticky.
The need therefore still exists for dispersions which make it possible to overcome these disadvantages and which are pleasant to use whatever the compounds which they contain.
The applicant has found, unexpectedly, vesicles which make it possible to achieve these objectives.